egutierrez
fd5787c55f
- .mcp.json - bash/functions/infra/write_mcp_jupyter_config.md - bash/functions/infra/write_mcp_jupyter_config.sh - cpp/CMakeLists.txt - cpp/apps/chart_demo - cpp/apps/shaders_lab - cpp/functions/gfx/gl_framebuffer.cpp - cpp/functions/gfx/gl_framebuffer.h - cpp/functions/gfx/gl_framebuffer.md - cpp/functions/gfx/mesh_gpu.md - ... Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
86 lines
3.0 KiB
Markdown
86 lines
3.0 KiB
Markdown
---
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name: gl_framebuffer
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kind: function
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lang: cpp
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domain: gfx
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version: "1.1.0"
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purity: impure
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signature: "void fb_init(Framebuffer& f); void fb_init_depth(Framebuffer& f); void fb_resize(Framebuffer& f, int w, int h); void fb_destroy(Framebuffer& f)"
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description: "CRUD de un framebuffer OpenGL (FBO + textura RGBA8, opcionalmente con depth renderbuffer GL_DEPTH_COMPONENT24). fb_init es color-only (retro-compat); fb_init_depth añade depth. fb_resize redimensiona color y depth si has_depth. Listo para uso con ImGui::Image."
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tags: [opengl, framebuffer, fbo, texture, gfx, offscreen, depth, cpp-dashboard-viz]
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uses_functions: ["gl_loader_cpp_gfx"]
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uses_types: []
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returns: []
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returns_optional: false
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error_type: "error_go_core"
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imports: [GL/gl.h, GL/glext.h]
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tested: false
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tests: []
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test_file_path: ""
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file_path: "cpp/functions/gfx/gl_framebuffer.cpp"
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framework: opengl
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params:
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- name: f
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desc: "Struct Framebuffer con campos fbo, tex, depth_rbo (GL ids), width, height, has_depth. Inicializar a {0} antes de fb_init/fb_init_depth."
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- name: w
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desc: "Ancho deseado en pixels (fb_resize)"
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- name: h
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desc: "Alto deseado en pixels (fb_resize)"
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output: "Modifica f in-place. Después de fb_init/fb_init_depth, f.fbo y f.tex son IDs GL válidos. Si fb_init_depth: f.depth_rbo != 0 y f.has_depth == true. fb_destroy pone todos los campos a 0."
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---
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# gl_framebuffer
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FBO con textura color RGBA8 (GL_CLAMP_TO_EDGE, GL_LINEAR). Opcionalmente con depth renderbuffer GL_DEPTH_COMPONENT24. Diseñado para renderizado offscreen y posterior display via `ImGui::Image`.
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## Ciclo de vida — color-only (retro-compat)
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```cpp
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fn::gfx::Framebuffer fb{};
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fn::gfx::fb_init(fb); // fbo + tex 1x1, has_depth=false
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// En el render loop:
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fn::gfx::fb_resize(fb, w, h); // no-op si mismas dimensiones
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// Al destruir:
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fn::gfx::fb_destroy(fb);
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```
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## Ciclo de vida — con depth renderbuffer
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```cpp
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fn::gfx::Framebuffer fb{};
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fn::gfx::fb_init_depth(fb); // fbo + tex 1x1 + depth_rbo 1x1, has_depth=true
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// En el render loop (antes de glDrawElements):
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glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
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glEnable(GL_DEPTH_TEST);
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glDepthFunc(GL_LESS);
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fn::gfx::fb_resize(fb, w, h); // redimensiona color Y depth_rbo
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// Al destruir:
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fn::gfx::fb_destroy(fb); // libera fbo, tex y depth_rbo
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```
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## Uso con ImGui::Image
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```cpp
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// Flip Y porque OpenGL tiene origen bottom-left
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ImGui::Image(
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reinterpret_cast<ImTextureID>(static_cast<uintptr_t>(fb.tex)),
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size,
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ImVec2(0, 1), ImVec2(1, 0)
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);
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```
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## Notas
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`fb_resize` recrea solo la textura (no el FBO) cuando las dimensiones cambian, reattachando la nueva textura al FBO existente. Para el depth renderbuffer, llama `glRenderbufferStorage` in-place (sin recrear el RBO). Esto minimiza el overhead de resize.
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`fb_init` (sin depth) se mantiene idéntico al comportamiento pre-v1.1.0 — no rompe consumidores existentes (`shader_canvas`, `graph_renderer`).
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## Capability growth log
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v1.1.0 (2026-05-28) — fb_init_depth opcional + depth en fb_resize/fb_destroy
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